--- a/mercurial/help.py	Fri Jan 15 12:56:25 2021 -0500
+++ b/mercurial/help.py	Wed Jan 13 22:37:21 2021 -0800
@@ -1064,7 +1064,7 @@
         if not rst:
             msg = _(b'no matches')
             hint = _(b"try 'hg help' for a list of topics")
-            raise error.Abort(msg, hint=hint)
+            raise error.InputError(msg, hint=hint)
     elif name and name != b'shortlist':
         queries = []
         if unknowncmd:
@@ -1095,7 +1095,7 @@
                     hintname = name
                 msg = _(b'no such help topic: %s') % formatname
                 hint = _(b"try 'hg help --keyword %s'") % hintname
-                raise error.Abort(msg, hint=hint)
+                raise error.InputError(msg, hint=hint)
     else:
         # program name
         if not ui.quiet:
@@ -1155,6 +1155,6 @@
     # to look for, or we could have simply failed to found "foo.bar"
     # because bar isn't a section of foo
     if section and not (blocks and name):
-        raise error.Abort(_(b"help section not found: %s") % fullname)
+        raise error.InputError(_(b"help section not found: %s") % fullname)
 
     return minirst.formatplain(blocks, textwidth)

--- a/tests/test-extdiff.t	Fri Jan 15 12:56:25 2021 -0500
+++ b/tests/test-extdiff.t	Wed Jan 13 22:37:21 2021 -0800
@@ -513,14 +513,14 @@
   $ HGPLAIN=1 hg --config hgext.extdiff= --config extdiff.cmd.td=hi help -k xyzzy
   abort: no matches
   (try 'hg help' for a list of topics)
-  [255]
+  [10]
 
   $ HGPLAIN=1 hg --config hgext.extdiff= --config extdiff.cmd.td=hi help td > /dev/null
 
   $ LC_MESSAGES=ja_JP.UTF-8 hg --config hgext.extdiff= --config extdiff.cmd.td=$U help -k xyzzy
   abort: no matches
   (try 'hg help' for a list of topics)
-  [255]
+  [10]
 
   $ LC_MESSAGES=ja_JP.UTF-8 hg --config hgext.extdiff= --config extdiff.cmd.td=$U help td \
   > | grep "^      '"

--- a/tests/test-help.t	Fri Jan 15 12:56:25 2021 -0500
+++ b/tests/test-help.t	Wed Jan 13 22:37:21 2021 -0800
@@ -758,7 +758,7 @@
   $ hg help foo
   abort: no such help topic: foo
   (try 'hg help --keyword foo')
-  [255]
+  [10]
 
   $ hg skjdfks
   hg: unknown command 'skjdfks'
@@ -1345,7 +1345,7 @@
   $ hg help internals.foo
   abort: no such help topic: internals.foo
   (try 'hg help --keyword foo')
-  [255]
+  [10]
 
 test advanced, deprecated and experimental options are hidden in command help
   $ hg help debugoptADV
@@ -1479,7 +1479,7 @@
 
   $ hg help config.annotate.git
   abort: help section not found: config.annotate.git
-  [255]
+  [10]
 
   $ hg help config.update.check
       "commands.update.check"
@@ -1509,7 +1509,7 @@
 
   $ hg help config.ommands.update.check
   abort: help section not found: config.ommands.update.check
-  [255]
+  [10]
 
 Unrelated trailing paragraphs shouldn't be included
 
@@ -1655,7 +1655,7 @@
   $ hg help -c schemes
   abort: no such help topic: schemes
   (try 'hg help --keyword schemes')
-  [255]
+  [10]
   $ hg help -e schemes |head -1
   schemes extension - extend schemes with shortcuts to repository swarms
   $ hg help -c -k dates |egrep '^(Topics|Extensions|Commands):'
@@ -1670,7 +1670,7 @@
   $ hg help -e commit
   abort: no such help topic: commit
   (try 'hg help --keyword commit')
-  [255]
+  [10]
 
 Test keyword search help
 
@@ -1715,14 +1715,14 @@
   $ hg help nonexistingtopicthatwillneverexisteverever
   abort: no such help topic: nonexistingtopicthatwillneverexisteverever
   (try 'hg help --keyword nonexistingtopicthatwillneverexisteverever')
-  [255]
+  [10]
 
 Test unfound keyword
 
   $ hg help --keyword nonexistingwordthatwillneverexisteverever
   abort: no matches
   (try 'hg help' for a list of topics)
-  [255]
+  [10]
 
 Test omit indicating for help
 
@@ -1869,11 +1869,11 @@
   
   $ hg help glossary.mcguffin
   abort: help section not found: glossary.mcguffin
-  [255]
+  [10]
 
   $ hg help glossary.mc.guffin
   abort: help section not found: glossary.mc.guffin
-  [255]
+  [10]
 
   $ hg help template.files
       files         List of strings. All files modified, added, or removed by